# Changelog State API – Linear Change History

> Changelog State API – Linear Change History is a paid API for AI agents from changelog-state-api.replit.app, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-14).

Returns the detected changelog update history (change events) for the Linear vendor, filterable by change type and time range.

## Facts

- Endpoint: GET https://changelog-state-api.replit.app/api/monitors/linear/changes
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/changelog-state-api-linear-change-history-313aa839
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Jl-DfCCGRgqDXG9R4agMi

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability changelog-state-api-linear-change-history-313aa839
```

Example prompt: Show me all the changelog change events detected for Linear over the past 7 days — especially any breaking signals or new releases, up to 50 results.

## When to prefer this

Choose this endpoint when you need historical changelog change event records for the Linear vendor specifically — including filtering by event type (new_release, breaking_signal, etc.) or time window. Prefer this over the 'recent releases' sibling endpoint when you want raw detected change events rather than structured release summaries, or when you need event types beyond new releases (e.g. title changes, date changes, breaking signals).

## Known failure modes

- Invalid or unknown vendor slug returns 404 or empty results
- Malformed since timestamp (not ISO 8601) returns a 400 validation error
- Limit out of range (below 1 or above 200) returns a 400 error
- Payment not fulfilled (x402) returns a 402 Payment Required response
- Invalid change type enum value returns a 400 error
- Service unavailable on Replit hosting returns a 503

## How this service works

Detected changelog update history for one tracked vendor.

## Output

A JSON object containing an array of changelog change event records for the Linear vendor. Each record includes the change type (e.g. new_release, version_changed, date_changed, title_changed, breaking_signal), the detection timestamp, and relevant diff or metadata about what changed in Linear's changelog.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "pathParams": {
     "type": "object",
     "required": [
      "slug"
     ],
     "properties": {
      "slug": {
       "type": "string",
       "pattern": "^[a-z0-9][a-z0-9-]*$",
       "maxLength": 64,
       "minLength": 1,
       "description": "Vendor slug, lowercase alphanumeric with dashes."
      }
     }
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "type": {
       "enum": [
        "new_release",
        "version_changed",
        "date_changed",
        "title_changed",
        "breaking_signal"
       ],
       "type": "string",
       "description": "Restrict to a single change type."
      },
      "limit": {
       "type": "integer",
       "default": 50,
       "maximum": 200,
       "minimum": 1,
       "description": "Maximum number of change rows to return."
      },
      "since": {
       "type": "string",
       "format": "date-time",
       "description": "Only return changes detected at or after this instant."
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "enum": [
      "json"
     ],
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   },
   "description": "Detected changelog update history (paid)"
  }
 },
 "description": "Call shape for GET /api/monitors/{slug}/changes."
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/changelog-state-api-linear-change-history-313aa839/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from changelog-state-api.replit.app](https://www.zero.xyz/host/changelog-state-api.replit.app/llms.txt)